Research note: an assessment of egg yolk structure using magnetic resonance imaging

The purpose of the present experiment was to examine the inner structure of the egg using magnetic resonance imaging (MRI). Proton images of fertile and infertile eggs and eggs from hens fed a corn-based or a flax-based diet were generated using a Spectroscopy Imaging Systems unit. Phantom eggs, made from homogenized albumen and homogenized yolk in a plastic shell, were imaged as controls. Eggs were imaged individually on their side, in the sagittal plane. A single image was generated through the center of the yolk. Images clearly distinguished the eggshell, air space, albumen, and yolk. Within the yolk of both fertile and infertile eggs, the latebra, the neck of the latebra, and four to six pairs of concentric yolk rings were visible, although the rings were less clearly defined in eggs from hens fed the flax-based diet. The embryo was not visible after 24 h of incubation but yolk stratification could still be resolved. Rings were not evident in the phantom eggs. It was concluded that MRI can be used successfully in assessing the microanatomy of eggs.